Vaporizing type burner with functional recirculating ring and central stack chamber



Jan. 25, 1955 c, GlLMORE 2,700,418

VAPORIZING TYPE BURNER WITH FUNCTIONAL RECIRCULATING RING AND CENTRAL STACK CHAMBER Filed July 28, 1951 FIG.

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f qhoncooooooooooooooooooooooo000000000005 e 25 o ,fB o o o o o o;. 25 25 25 3s 37 I 00 o o 7 o o INVENTOR. CLEMENT R. GILMORE QQ QLF- ATTORNEYS United States Patent-O VAPORIZING TYPE BURNER WITH FUNCTIONAL RECIRCULATING RING AND CENTRAL STACK CHAMBER Clement R. Gilmore, Shaker Heights, Ohio Application July 28, 1951, Serial No. 239,119

4 Claims. (Cl. 158-91) This invention relates to oil burners, and particularly to oil burners of the vaporizing type in which liquid oil is volatilized to provide a super-rich vapor-air mixture which is further mingled with additional air to provide a combustible vapor-air mixture.

The present application is a continuation-in-part of my co-pending application, Serial No. 225,215, filed May 8, 1951, in which a burner is disclosed wherein air and volatilized gas are constrained to recirculate in a tight circuitous path over the surface of the fuel oil. This recirculation remarkably improves combustion at low fire by eliminating the loose ends" and smoking which have been previously encountered at this stage. The recirculation is particularly important in that it greatly increases burner capacity by increasing the rate of volatilization and combustion of the fuel oil.

The present invention embodies the recirculation principle and further provides a central chamber or stack which performs the double function of providing a conduit'through which gases in the middle and upper portions of the retort chamber are pulled downwardly toward the bottom of the chamber and also providing a striking point to force gases on the outside of the stack to pass downwardly ad,acent the stack and then to pass upwardly away from the center and towards the walls and air inlets of the chamber, as will be more fully explained below. The present burner has an even higher capacity for a given size than does the burner disclosed in my co-pending application referred to above. Complete combustion and absence of smoke throughout the rise to and during full fire is attained by the present burner regardless of whether distillate or catalytic cracked oil is burned. The recirculator makes possible a very low but clean pilot fire and this feature, together with the high capacity at full fire gives the burner a very high turn-down ratio enabling the burner to operate on pilot fire at a small fraction of its full capacity.

One very objectionable and dangerous characteristic of the faster burning vaporizing burners has been their tendency to run away with themselves when they are ignited in the puddled or flooded condition. The resulting abnormal flame which may extend far beyond the burner constitutes a very bad fire hazard which precludes safe commercial, domestic or military utilization of the burner. A particular object and advantage of the present burner is the provision of a very simple means to enable the burner to throttle itself when in the puddled or flooded condition so that any abnormally large fire will be avoided and the burner will operate safely at all times.

In addition to the above advantages, the present burner burns cleanly at all stages and is subject to a minimum of carbon deposit. The burner is also very responsive to oil and air flow control and will advance rapidly from pilot fire to full fire or to any intermediate stage and will shift rapidly from any stage to any other stage for which it is set. Moreover, as to any given stage, the burner is flexible through a range of air-oil inputs.

Other objects and advantages of the invention will become apparent from an examination of the following specification and the drawings, in which:

Figure 1 is an elevation in section of my invention.

Figure 2 is a view in section taken on line 22 in Figure l.

The figures illustrate a pot burner having an outer housing 20, a retort chamber or pot 21 and a flange 22 2,700,418 Patented Jan. 25, 1955 2 defining jacket chamber 23. Air is supplied to the retort chamber through the inlet aperture 24. The wall of the retort chamber is provided with a plurality of air inlets 25 admitting air from the jacket chamber 23. The bottom row of air inlet holes is preferably tipped downwardly as shown in Figure 1. The base of the retort chamber 21 is dished to define a concave bottom 26 to which oil is admitted through oil inlet 27.

Supported on the bottom of the chamber by the legs 31 is a stack or cylinder 32. The legs space the stack 32 from the chamber bottom to form spaces or slots 33. Locatedlongitudinally upwardly along the stack are additional slots 34 and 35. The top of the cylinder 32 is capped by a cover 36 which is hinged to the stack at 37.

A recirculating ring 40 surrounds the cylinder 32 and is supported on the bottom of the retort chamber by the legs 41. To assure proper centering of the ring 40, radially extending spacers (not shown) extending to or from the side walls of the chamber 21 or to or from the stack 32 may be provided. An additional recirculating ring 43 may be provided above the ring 40. The ring 43 also surrounds" the stack 32 and is supported on the ring 40 by the legs 44, and may also be provided with induce rapid circular motion of gaseous vapors around the recirculating rings as indicated by arrows in Figure 1. This circular motion describes a tight annular toroid path and results in rapid sweeping of oil in the bottom of the chamber 21 by recirculating air. Air is constantly supplied to the torus of circulating air and oil vapor and a vapor-air mixture constantly rises from the toroid path radially outwardly and upwardly toward the top of the chamber 21 crossing the path of the air supply jets.

The rapid recirculation around the lower rings also induces a flow of air and oil vapor outwardly through the bottom slot 33. Air and oil vapor drawn out through the bottom slot is replaced by gaseous fluids which flow into the stack 32 through the slots 34 and 35. There is a loose or large path of circulation of gases downwardly through the inside and adjacent the outside of the stack 32 and upwardly adjacent the walls of the chamber 21. The walls of the stack 32 function to define the large circulating path and also constrain upwardly moving gases away from the center and toward the walls of the chamber 21. Due to this constraint, incoming air admitted through the inlets 25 immediately enters the super-rich mixture rising from the bottom of the retort chamber. The small flame fronts which occur at these points of entry are sharp and well defined, completely eliminating the smoking and loss of capacity due to faulty combustion which has occurred in previous burners when it was necessary for the air in the incoming jets to move a considerable distance inwardly before encountering the super-rich vapor-air mixture which it is to enter. The absorption and mixing of excess uncombined oxygen which passes through each small flame front at each jet is thus cleanly and quickly effected.

The provision of the stack 32 materially increases the rate of vaporization, the rate of gas generation and the capacity of the burner. While the reasons for this increase are not clearly understood, it is believed that the loose large path of circulation of gaseous fluids down through the stack 32 and up the sides of the retort chamber enhances the intimate mixing action attained in the tight annular toroid path of moving gases adjacent the bottom of the retort chamber by subjecting air added at higher levels in the retort chamber to the mixing action. In addition, volatilization of the liquid oil is accelerated by the return down through and adjacent to the stack 32 of hot gases which sweep over substantially all of the relatively large surface area of liquid oil.

A retort chamber having a domed and guttered bottom similar to that illustrated in my aforesaid co-pending application, Serial No. 225,215, may be employed in connection with my present invention. The flat gutter of such a burner must, however, be carefully and exactly levelled on installation to insure that incoming oil will be distributed around the entire circumference of the retort bottom. For this reason the present invention is illustrated with the concave retort chamber bottom 26 which does not necessitate very careful levelling upon installation of the burner. v

If the liquid fuel oil contained in the concave bottom 26 is in a puddled condition and reaches a great enough depth to cut offthe slots 33, circulation of gases down through the stack 32 is not eliminated because the pressure outside the slots 34 is lower than the pressure outside the slots 35 due to the rapid downward movement of gases past the slots 34. Accordingly, gases are forced inwardly through the slots 35 and are drawn downwardly and outwardly through the slots 34. However, restriction of the slots 33 by the oil itself serves to keep the burner from running away with itself when lit in a puddled condition.

In order to promote intimate mixing of air and oil vapor at higher stages and completeness of combustion in the retort chamber to further augment capacity and cleanliness, in some installations it has been found desirable to increase both the mean length of the paths described by rising gases and the degree of turbulence in higher portions of the pot by providing one or more additional rings such as ring 50 which may be suitably supported as by legs 51 which rest upon the lower rings. The action of the rising gases and incoming air will actually induce circulation around ring 50 in the same direction as the circulation around the lower rings. When catalytic fuel oil is burned, it is particularly important to include the upper rings in order to provide a hot surface over and around which free carbon contained in the rising gases is passed and heated to a suflicient temperature to chemically combine with the rising gases.

Direct exposure of the liquid oil on the bottom of the retort chamber to the relatively intense flames at any stage of fire together with the down-sweeping vapors through the stack 32 is unsatisfactory because of the likelihood that the liquid oil will be cracked by the great amount of heat carried and radiated down to it to produce highly undesirable tarry deposits and carbon formation in the retort chamber or in the heating unit in which the burner is employed. Accordingly, it is preferable to leave the lid 36 in the closed position while the burner is operating. The lid acts to shield the liquid oil from the radiant heat of the high fire flame and precludes any recirculation of gases from the upper portions of the retort chamber over and above that recirculation which is designed into the burner. However, the hinge 37 is provided to enable the burner to be conveniently ignited. With the lid raised, burning igniting material such as paper may be dropped into the stack 32. The open stack acts as a flue for the burning igniting material for a few moments until air circulating around the ring 40 draws the igniting flame out through the slots 33 (or through slots 34 if the slots 33 are completely immersed in oil) to quickly induce initial vaporization and combustion of the oil. The lid 36 -is then closed and the vaporization and combustion around the ring 40 supports itself as the igniting material is completely consumed.

It will be apparent to those conversant with the oil burner field that many alterations may be made in the specific embodiment disclosed without departing from the teaching of the invention. For instance, as mentioned above, the retort bottom need not necessarily be concave. The slots 33, 34, and 35 maybe varied in num ber and location or may be replaced by rows or zones of holes. The lid 36 may be simply removable rather than hinged. The stack 32 has been illustrated as a cylinder, but it may be advantageous to give it the shape of an inverted truncated cone 011? whose inwardly and downwardly slanting sides incoming air from the inlets 25 will be deflected toward the bottom of the retort chamber. Many other modifications of particular structural details will readily suggest themselves, and, accordingly, the scope of the invention is not to be limited to the illustrated embodiment, but is to be determined by the following claims.

What is claimed is:

1. In a liquid fuel burner, a retort chamber having the shape of a pot with an inner closed end and an outer open end, aperture means to admit air at a plurality of longitudinal and circumferential locations on the sidewalls of said retort chamber, means to admit liquid fuel in said retort chamber whereby fuel vapors will occur in said retort. chamber, bafiie means within said retort chamber, said baffle means comprising ring means and means defining a central covered chamber having slotted side walls, said slots extending through said sidewalls, at least one of said slots being adjacent said inner closed end, at least one ring of said ring means being located between said central chamber and the sidewalls of said retort chamber, said at least one ring having a radially outer edge spaced from the sidewalls of said retort chamber and a radially inner edge spaced from the sidewalls of said central chamber, the innermost of said aperture means being operatively associated with said radially outer edge to direct incoming air along paths passing over and adjacent to said radially outer edge on the outermost side of said at least one ring, whereby said fuel vapors are induced to move outwardly toward said outer open end along continuous longitudinal paths at the longitudinal location of said baflie means solely through peripheral portions of said pot and a majorityof said outwardly moving vapors will cross the paths of air admitted through said aperture means and a majority of the movement of vapor air along sidewalls of said central chamber will be in an inward direction toward said inner closed end. 7

2. In a liquid fuel burner, a retort chamber having the shape of a pot with an inner closed end and an outer open end, aperture means to admit air at a plurality of vertical and circumferential locations on the sidewalls of said retort chamber, means to admit liquid fuel in said retort chamber, baflie means within said retort chamber, said baffle means comprising ring means and means defining a central covered chamber having slotted sidewalls, said slots extending through said sidewalls, at least one of said slots being adjacent said inner closed end, at least one ring of said ring means being located between said central chamber and the sidewalls of said retort chamber, said at least one ring having a radially outer edge spaced from the sidewalls of said retort chamber and a radially inner edge spaced from the sidewalls of said central chamber, the lowermost of said aperture means being operatively associated with said radially outer edge to direct incoming air along paths passing over and adjacent to said radially outer edge on the uppermost side of said at least one ring, whereby fuel vapors are induced to move upwardly toward said outer open end along continuous vertical paths at the yerticallocation of said baflie means solely through peripheral portions of said pot and a majority of said upwardly moving vapors will cross the paths of air admittedthrough said aperture means and a majority of the movement of vapor air along sidewalls of said central chamber will be in a downward direction toward said inner closed end.

3. In a liquid fuel burner, a retort chamber having the shape of a pot with an inner closed end and an outer open end, aperture means to admit air at a plurality of longitudinal and circumferential locations on the sidewalls of said retort chamber, means to admit liquid fuel in said retort chamber whereby fuel vapors will occur in said retort chamber, bafile means within said retort chamber, said baflie means comprising ring means and means defining a central covered chamber having slotted side walls, said slots'extending through said sidewalls, at least one of said slots being adjacent said inner closed end, at least one ring of said ringmeans being located between said central chamber and the sidewalls of said retort chamber, said at least one ring having a radially outer edge spaced from the sidewalls of said retort chamber, at least another one of said slots being located adjacent said at least one ring on the axially outermost side thereof, the innermost of said aperture means being operatively associated with said radially outer edge to direct incoming air along paths passing over and adjacent to said radially outer edge on the outermost side of said'at least one ring, whereby said fuel vapors are induced to move outwardly toward said outer open end along continuous logitudinal paths at thelongitudinal location of said baffle means solely through peripheral portions of said pot and a majority ofsaid outwardly moving vapors will cross the paths of air admitted through said aperture means and a majority of the movement of vapor air along sidewalls of said' central chamber will be in an inward direction toward said inner closed end'.

4. In a liquid fuelburner, a retort chamber having the shape of a'pot with an inner closed end and an outer open end, aperturemean's'to admit air at a plurality of vertical and circumferential locations on the sidewalls of said retort chamber, means to admit liquid fuel in said retort chamber, bafiie means within said retort chamber, said baffle means comprising ring means and means defining a central covered chamber having slotted sidewalls, said slots extending through said sidewalls, at least one of said slots being adjacent said inner closed end, at least one ring of said ring means being located between said central chamber and the sidewalls of said retort chamber, said at least one ring having a radially outer edge spaced from the sidewalls of said retort chamber, at least another one of said slots being located immediately above said at least one ring, the lowermost of said aperture means being operatively associated with said radially outer edge to direct incoming air along paths passing over and adjacent to said radially outer edge on the uppermost side of said at least one ring, whereby fuel vapors are induced to move upwardly toward said outer open end along continuous vertical paths at the vertical location of said baffie means solely through peripheral portions of said pot and a majority of said upwardly moving vapors will cross the paths of air admitted through said aperture means and a majority of the movement of vapor air along sidewalls of said central chamher will be in a downward direction toward said inner closed end.

References Cited in the file of this patent UNITED STATES PATENTS 1,879,011 Appel Sept. 27, 1932 2,258,679 Hayter Oct. 14, 1941 2,339,637 Hayter Jan. 18, 1944 

